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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
be6e6707 | 2 | /* RxRPC remote transport endpoint record management |
17926a79 | 3 | * |
be6e6707 | 4 | * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved. |
17926a79 | 5 | * Written by David Howells (dhowells@redhat.com) |
17926a79 DH |
6 | */ |
7 | ||
9b6d5398 JP |
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
9 | ||
17926a79 DH |
10 | #include <linux/module.h> |
11 | #include <linux/net.h> | |
12 | #include <linux/skbuff.h> | |
13 | #include <linux/udp.h> | |
14 | #include <linux/in.h> | |
75b54cb5 | 15 | #include <linux/in6.h> |
5a0e3ad6 | 16 | #include <linux/slab.h> |
be6e6707 | 17 | #include <linux/hashtable.h> |
17926a79 DH |
18 | #include <net/sock.h> |
19 | #include <net/af_rxrpc.h> | |
20 | #include <net/ip.h> | |
224711df | 21 | #include <net/route.h> |
75b54cb5 | 22 | #include <net/ip6_route.h> |
17926a79 DH |
23 | #include "ar-internal.h" |
24 | ||
be6e6707 DH |
25 | /* |
26 | * Hash a peer key. | |
27 | */ | |
28 | static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local, | |
29 | const struct sockaddr_rxrpc *srx) | |
30 | { | |
31 | const u16 *p; | |
32 | unsigned int i, size; | |
33 | unsigned long hash_key; | |
34 | ||
35 | _enter(""); | |
36 | ||
37 | hash_key = (unsigned long)local / __alignof__(*local); | |
38 | hash_key += srx->transport_type; | |
39 | hash_key += srx->transport_len; | |
40 | hash_key += srx->transport.family; | |
41 | ||
42 | switch (srx->transport.family) { | |
43 | case AF_INET: | |
44 | hash_key += (u16 __force)srx->transport.sin.sin_port; | |
45 | size = sizeof(srx->transport.sin.sin_addr); | |
46 | p = (u16 *)&srx->transport.sin.sin_addr; | |
47 | break; | |
d1912747 | 48 | #ifdef CONFIG_AF_RXRPC_IPV6 |
75b54cb5 DH |
49 | case AF_INET6: |
50 | hash_key += (u16 __force)srx->transport.sin.sin_port; | |
51 | size = sizeof(srx->transport.sin6.sin6_addr); | |
52 | p = (u16 *)&srx->transport.sin6.sin6_addr; | |
53 | break; | |
d1912747 | 54 | #endif |
2f9f9f52 AB |
55 | default: |
56 | WARN(1, "AF_RXRPC: Unsupported transport address family\n"); | |
57 | return 0; | |
be6e6707 DH |
58 | } |
59 | ||
60 | /* Step through the peer address in 16-bit portions for speed */ | |
61 | for (i = 0; i < size; i += sizeof(*p), p++) | |
62 | hash_key += *p; | |
63 | ||
64 | _leave(" 0x%lx", hash_key); | |
65 | return hash_key; | |
66 | } | |
67 | ||
68 | /* | |
69 | * Compare a peer to a key. Return -ve, 0 or +ve to indicate less than, same | |
70 | * or greater than. | |
71 | * | |
72 | * Unfortunately, the primitives in linux/hashtable.h don't allow for sorted | |
73 | * buckets and mid-bucket insertion, so we don't make full use of this | |
74 | * information at this point. | |
75 | */ | |
76 | static long rxrpc_peer_cmp_key(const struct rxrpc_peer *peer, | |
77 | struct rxrpc_local *local, | |
78 | const struct sockaddr_rxrpc *srx, | |
79 | unsigned long hash_key) | |
80 | { | |
81 | long diff; | |
82 | ||
83 | diff = ((peer->hash_key - hash_key) ?: | |
84 | ((unsigned long)peer->local - (unsigned long)local) ?: | |
85 | (peer->srx.transport_type - srx->transport_type) ?: | |
86 | (peer->srx.transport_len - srx->transport_len) ?: | |
87 | (peer->srx.transport.family - srx->transport.family)); | |
88 | if (diff != 0) | |
89 | return diff; | |
90 | ||
91 | switch (srx->transport.family) { | |
92 | case AF_INET: | |
93 | return ((u16 __force)peer->srx.transport.sin.sin_port - | |
94 | (u16 __force)srx->transport.sin.sin_port) ?: | |
95 | memcmp(&peer->srx.transport.sin.sin_addr, | |
96 | &srx->transport.sin.sin_addr, | |
97 | sizeof(struct in_addr)); | |
d1912747 | 98 | #ifdef CONFIG_AF_RXRPC_IPV6 |
75b54cb5 DH |
99 | case AF_INET6: |
100 | return ((u16 __force)peer->srx.transport.sin6.sin6_port - | |
101 | (u16 __force)srx->transport.sin6.sin6_port) ?: | |
102 | memcmp(&peer->srx.transport.sin6.sin6_addr, | |
103 | &srx->transport.sin6.sin6_addr, | |
104 | sizeof(struct in6_addr)); | |
d1912747 | 105 | #endif |
be6e6707 DH |
106 | default: |
107 | BUG(); | |
108 | } | |
109 | } | |
110 | ||
111 | /* | |
112 | * Look up a remote transport endpoint for the specified address using RCU. | |
113 | */ | |
114 | static struct rxrpc_peer *__rxrpc_lookup_peer_rcu( | |
115 | struct rxrpc_local *local, | |
116 | const struct sockaddr_rxrpc *srx, | |
117 | unsigned long hash_key) | |
118 | { | |
119 | struct rxrpc_peer *peer; | |
2baec2c3 | 120 | struct rxrpc_net *rxnet = local->rxnet; |
be6e6707 | 121 | |
2baec2c3 | 122 | hash_for_each_possible_rcu(rxnet->peer_hash, peer, hash_link, hash_key) { |
0099dc58 DH |
123 | if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0 && |
124 | atomic_read(&peer->usage) > 0) | |
be6e6707 | 125 | return peer; |
be6e6707 DH |
126 | } |
127 | ||
128 | return NULL; | |
129 | } | |
130 | ||
131 | /* | |
132 | * Look up a remote transport endpoint for the specified address using RCU. | |
133 | */ | |
134 | struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *local, | |
135 | const struct sockaddr_rxrpc *srx) | |
136 | { | |
137 | struct rxrpc_peer *peer; | |
138 | unsigned long hash_key = rxrpc_peer_hash_key(local, srx); | |
139 | ||
140 | peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key); | |
141 | if (peer) { | |
75b54cb5 | 142 | _net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport); |
be6e6707 DH |
143 | _leave(" = %p {u=%d}", peer, atomic_read(&peer->usage)); |
144 | } | |
145 | return peer; | |
146 | } | |
17926a79 | 147 | |
224711df DH |
148 | /* |
149 | * assess the MTU size for the network interface through which this peer is | |
150 | * reached | |
151 | */ | |
5e33a23b DH |
152 | static void rxrpc_assess_MTU_size(struct rxrpc_sock *rx, |
153 | struct rxrpc_peer *peer) | |
224711df | 154 | { |
5e33a23b | 155 | struct net *net = sock_net(&rx->sk); |
75b54cb5 | 156 | struct dst_entry *dst; |
224711df | 157 | struct rtable *rt; |
75b54cb5 DH |
158 | struct flowi fl; |
159 | struct flowi4 *fl4 = &fl.u.ip4; | |
d1912747 | 160 | #ifdef CONFIG_AF_RXRPC_IPV6 |
75b54cb5 | 161 | struct flowi6 *fl6 = &fl.u.ip6; |
d1912747 | 162 | #endif |
224711df DH |
163 | |
164 | peer->if_mtu = 1500; | |
165 | ||
75b54cb5 DH |
166 | memset(&fl, 0, sizeof(fl)); |
167 | switch (peer->srx.transport.family) { | |
168 | case AF_INET: | |
169 | rt = ip_route_output_ports( | |
5e33a23b | 170 | net, fl4, NULL, |
75b54cb5 DH |
171 | peer->srx.transport.sin.sin_addr.s_addr, 0, |
172 | htons(7000), htons(7001), IPPROTO_UDP, 0, 0); | |
173 | if (IS_ERR(rt)) { | |
174 | _leave(" [route err %ld]", PTR_ERR(rt)); | |
175 | return; | |
176 | } | |
177 | dst = &rt->dst; | |
178 | break; | |
179 | ||
d1912747 | 180 | #ifdef CONFIG_AF_RXRPC_IPV6 |
75b54cb5 DH |
181 | case AF_INET6: |
182 | fl6->flowi6_iif = LOOPBACK_IFINDEX; | |
183 | fl6->flowi6_scope = RT_SCOPE_UNIVERSE; | |
184 | fl6->flowi6_proto = IPPROTO_UDP; | |
185 | memcpy(&fl6->daddr, &peer->srx.transport.sin6.sin6_addr, | |
186 | sizeof(struct in6_addr)); | |
187 | fl6->fl6_dport = htons(7001); | |
188 | fl6->fl6_sport = htons(7000); | |
5e33a23b | 189 | dst = ip6_route_output(net, NULL, fl6); |
07096f61 DH |
190 | if (dst->error) { |
191 | _leave(" [route err %d]", dst->error); | |
75b54cb5 DH |
192 | return; |
193 | } | |
194 | break; | |
d1912747 | 195 | #endif |
75b54cb5 DH |
196 | |
197 | default: | |
198 | BUG(); | |
224711df DH |
199 | } |
200 | ||
75b54cb5 DH |
201 | peer->if_mtu = dst_mtu(dst); |
202 | dst_release(dst); | |
224711df | 203 | |
a6a62b69 | 204 | _leave(" [if_mtu %u]", peer->if_mtu); |
224711df DH |
205 | } |
206 | ||
17926a79 | 207 | /* |
be6e6707 | 208 | * Allocate a peer. |
17926a79 | 209 | */ |
be6e6707 | 210 | struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *local, gfp_t gfp) |
17926a79 | 211 | { |
033b2c7f | 212 | const void *here = __builtin_return_address(0); |
17926a79 DH |
213 | struct rxrpc_peer *peer; |
214 | ||
215 | _enter(""); | |
216 | ||
217 | peer = kzalloc(sizeof(struct rxrpc_peer), gfp); | |
218 | if (peer) { | |
be6e6707 | 219 | atomic_set(&peer->usage, 1); |
9ebeddef | 220 | peer->local = rxrpc_get_local(local); |
f66d7490 | 221 | INIT_HLIST_HEAD(&peer->error_targets); |
aa390bbe | 222 | peer->service_conns = RB_ROOT; |
8496af50 | 223 | seqlock_init(&peer->service_conn_lock); |
17926a79 | 224 | spin_lock_init(&peer->lock); |
c1e15b49 | 225 | spin_lock_init(&peer->rtt_input_lock); |
17926a79 | 226 | peer->debug_id = atomic_inc_return(&rxrpc_debug_id); |
f7aec129 | 227 | |
c410bf01 DH |
228 | rxrpc_peer_init_rtt(peer); |
229 | ||
f7aec129 DH |
230 | if (RXRPC_TX_SMSS > 2190) |
231 | peer->cong_cwnd = 2; | |
232 | else if (RXRPC_TX_SMSS > 1095) | |
233 | peer->cong_cwnd = 3; | |
234 | else | |
235 | peer->cong_cwnd = 4; | |
2f184393 | 236 | trace_rxrpc_peer(peer->debug_id, rxrpc_peer_new, 1, here); |
be6e6707 DH |
237 | } |
238 | ||
239 | _leave(" = %p", peer); | |
240 | return peer; | |
241 | } | |
242 | ||
248f219c DH |
243 | /* |
244 | * Initialise peer record. | |
245 | */ | |
5e33a23b DH |
246 | static void rxrpc_init_peer(struct rxrpc_sock *rx, struct rxrpc_peer *peer, |
247 | unsigned long hash_key) | |
248f219c | 248 | { |
08a39685 | 249 | peer->hash_key = hash_key; |
5e33a23b | 250 | rxrpc_assess_MTU_size(rx, peer); |
248f219c | 251 | peer->mtu = peer->if_mtu; |
0d4b103c | 252 | peer->rtt_last_req = ktime_get_real(); |
248f219c | 253 | |
75b54cb5 DH |
254 | switch (peer->srx.transport.family) { |
255 | case AF_INET: | |
248f219c | 256 | peer->hdrsize = sizeof(struct iphdr); |
75b54cb5 | 257 | break; |
d1912747 | 258 | #ifdef CONFIG_AF_RXRPC_IPV6 |
75b54cb5 DH |
259 | case AF_INET6: |
260 | peer->hdrsize = sizeof(struct ipv6hdr); | |
261 | break; | |
d1912747 | 262 | #endif |
75b54cb5 DH |
263 | default: |
264 | BUG(); | |
265 | } | |
266 | ||
267 | switch (peer->srx.transport_type) { | |
268 | case SOCK_DGRAM: | |
269 | peer->hdrsize += sizeof(struct udphdr); | |
270 | break; | |
271 | default: | |
248f219c DH |
272 | BUG(); |
273 | } | |
274 | ||
275 | peer->hdrsize += sizeof(struct rxrpc_wire_header); | |
276 | peer->maxdata = peer->mtu - peer->hdrsize; | |
277 | } | |
278 | ||
be6e6707 DH |
279 | /* |
280 | * Set up a new peer. | |
281 | */ | |
5e33a23b DH |
282 | static struct rxrpc_peer *rxrpc_create_peer(struct rxrpc_sock *rx, |
283 | struct rxrpc_local *local, | |
be6e6707 DH |
284 | struct sockaddr_rxrpc *srx, |
285 | unsigned long hash_key, | |
286 | gfp_t gfp) | |
287 | { | |
288 | struct rxrpc_peer *peer; | |
289 | ||
290 | _enter(""); | |
291 | ||
292 | peer = rxrpc_alloc_peer(local, gfp); | |
293 | if (peer) { | |
17926a79 | 294 | memcpy(&peer->srx, srx, sizeof(*srx)); |
5e33a23b | 295 | rxrpc_init_peer(rx, peer, hash_key); |
248f219c | 296 | } |
17926a79 | 297 | |
248f219c DH |
298 | _leave(" = %p", peer); |
299 | return peer; | |
300 | } | |
17926a79 | 301 | |
248f219c | 302 | /* |
0099dc58 DH |
303 | * Set up a new incoming peer. There shouldn't be any other matching peers |
304 | * since we've already done a search in the list from the non-reentrant context | |
305 | * (the data_ready handler) that is the only place we can add new peers. | |
248f219c | 306 | */ |
5e33a23b DH |
307 | void rxrpc_new_incoming_peer(struct rxrpc_sock *rx, struct rxrpc_local *local, |
308 | struct rxrpc_peer *peer) | |
248f219c | 309 | { |
2baec2c3 | 310 | struct rxrpc_net *rxnet = local->rxnet; |
248f219c DH |
311 | unsigned long hash_key; |
312 | ||
0099dc58 | 313 | hash_key = rxrpc_peer_hash_key(local, &peer->srx); |
5e33a23b | 314 | rxrpc_init_peer(rx, peer, hash_key); |
248f219c | 315 | |
2baec2c3 | 316 | spin_lock(&rxnet->peer_hash_lock); |
0099dc58 DH |
317 | hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key); |
318 | list_add_tail(&peer->keepalive_link, &rxnet->peer_keepalive_new); | |
2baec2c3 | 319 | spin_unlock(&rxnet->peer_hash_lock); |
17926a79 DH |
320 | } |
321 | ||
322 | /* | |
323 | * obtain a remote transport endpoint for the specified address | |
324 | */ | |
5e33a23b DH |
325 | struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_sock *rx, |
326 | struct rxrpc_local *local, | |
be6e6707 | 327 | struct sockaddr_rxrpc *srx, gfp_t gfp) |
17926a79 DH |
328 | { |
329 | struct rxrpc_peer *peer, *candidate; | |
2baec2c3 | 330 | struct rxrpc_net *rxnet = local->rxnet; |
be6e6707 | 331 | unsigned long hash_key = rxrpc_peer_hash_key(local, srx); |
17926a79 | 332 | |
75b54cb5 | 333 | _enter("{%pISp}", &srx->transport); |
17926a79 DH |
334 | |
335 | /* search the peer list first */ | |
be6e6707 DH |
336 | rcu_read_lock(); |
337 | peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key); | |
338 | if (peer && !rxrpc_get_peer_maybe(peer)) | |
339 | peer = NULL; | |
340 | rcu_read_unlock(); | |
341 | ||
342 | if (!peer) { | |
343 | /* The peer is not yet present in hash - create a candidate | |
344 | * for a new record and then redo the search. | |
345 | */ | |
5e33a23b | 346 | candidate = rxrpc_create_peer(rx, local, srx, hash_key, gfp); |
be6e6707 DH |
347 | if (!candidate) { |
348 | _leave(" = NULL [nomem]"); | |
349 | return NULL; | |
350 | } | |
17926a79 | 351 | |
2baec2c3 | 352 | spin_lock_bh(&rxnet->peer_hash_lock); |
17926a79 | 353 | |
be6e6707 DH |
354 | /* Need to check that we aren't racing with someone else */ |
355 | peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key); | |
356 | if (peer && !rxrpc_get_peer_maybe(peer)) | |
357 | peer = NULL; | |
ace45bec | 358 | if (!peer) { |
2baec2c3 | 359 | hash_add_rcu(rxnet->peer_hash, |
be6e6707 | 360 | &candidate->hash_link, hash_key); |
330bdcfa DH |
361 | list_add_tail(&candidate->keepalive_link, |
362 | &rxnet->peer_keepalive_new); | |
ace45bec | 363 | } |
17926a79 | 364 | |
2baec2c3 | 365 | spin_unlock_bh(&rxnet->peer_hash_lock); |
17926a79 | 366 | |
be6e6707 DH |
367 | if (peer) |
368 | kfree(candidate); | |
369 | else | |
370 | peer = candidate; | |
371 | } | |
17926a79 | 372 | |
75b54cb5 | 373 | _net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport); |
17926a79 | 374 | |
be6e6707 | 375 | _leave(" = %p {u=%d}", peer, atomic_read(&peer->usage)); |
17926a79 | 376 | return peer; |
17926a79 DH |
377 | } |
378 | ||
379 | /* | |
1159d4b4 | 380 | * Get a ref on a peer record. |
17926a79 | 381 | */ |
1159d4b4 DH |
382 | struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer) |
383 | { | |
384 | const void *here = __builtin_return_address(0); | |
385 | int n; | |
386 | ||
387 | n = atomic_inc_return(&peer->usage); | |
55f6c98e | 388 | trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, n, here); |
1159d4b4 DH |
389 | return peer; |
390 | } | |
391 | ||
392 | /* | |
393 | * Get a ref on a peer record unless its usage has already reached 0. | |
394 | */ | |
395 | struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *peer) | |
396 | { | |
397 | const void *here = __builtin_return_address(0); | |
398 | ||
399 | if (peer) { | |
bfc18e38 | 400 | int n = atomic_fetch_add_unless(&peer->usage, 1, 0); |
1159d4b4 | 401 | if (n > 0) |
55f6c98e | 402 | trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, n + 1, here); |
1159d4b4 DH |
403 | else |
404 | peer = NULL; | |
405 | } | |
406 | return peer; | |
407 | } | |
408 | ||
1159d4b4 DH |
409 | /* |
410 | * Discard a peer record. | |
411 | */ | |
412 | static void __rxrpc_put_peer(struct rxrpc_peer *peer) | |
17926a79 | 413 | { |
2baec2c3 DH |
414 | struct rxrpc_net *rxnet = peer->local->rxnet; |
415 | ||
f66d7490 | 416 | ASSERT(hlist_empty(&peer->error_targets)); |
17926a79 | 417 | |
2baec2c3 | 418 | spin_lock_bh(&rxnet->peer_hash_lock); |
be6e6707 | 419 | hash_del_rcu(&peer->hash_link); |
330bdcfa | 420 | list_del_init(&peer->keepalive_link); |
2baec2c3 | 421 | spin_unlock_bh(&rxnet->peer_hash_lock); |
17926a79 | 422 | |
9ebeddef | 423 | rxrpc_put_local(peer->local); |
be6e6707 | 424 | kfree_rcu(peer, rcu); |
17926a79 | 425 | } |
8324f0bc | 426 | |
1159d4b4 DH |
427 | /* |
428 | * Drop a ref on a peer record. | |
429 | */ | |
430 | void rxrpc_put_peer(struct rxrpc_peer *peer) | |
431 | { | |
432 | const void *here = __builtin_return_address(0); | |
55f6c98e | 433 | unsigned int debug_id; |
1159d4b4 DH |
434 | int n; |
435 | ||
436 | if (peer) { | |
55f6c98e | 437 | debug_id = peer->debug_id; |
1159d4b4 | 438 | n = atomic_dec_return(&peer->usage); |
55f6c98e | 439 | trace_rxrpc_peer(debug_id, rxrpc_peer_put, n, here); |
1159d4b4 DH |
440 | if (n == 0) |
441 | __rxrpc_put_peer(peer); | |
442 | } | |
443 | } | |
444 | ||
60034d3d DH |
445 | /* |
446 | * Drop a ref on a peer record where the caller already holds the | |
447 | * peer_hash_lock. | |
448 | */ | |
449 | void rxrpc_put_peer_locked(struct rxrpc_peer *peer) | |
450 | { | |
451 | const void *here = __builtin_return_address(0); | |
55f6c98e | 452 | unsigned int debug_id = peer->debug_id; |
60034d3d DH |
453 | int n; |
454 | ||
455 | n = atomic_dec_return(&peer->usage); | |
55f6c98e | 456 | trace_rxrpc_peer(debug_id, rxrpc_peer_put, n, here); |
60034d3d DH |
457 | if (n == 0) { |
458 | hash_del_rcu(&peer->hash_link); | |
459 | list_del_init(&peer->keepalive_link); | |
9ebeddef | 460 | rxrpc_put_local(peer->local); |
60034d3d DH |
461 | kfree_rcu(peer, rcu); |
462 | } | |
463 | } | |
464 | ||
17226f12 DH |
465 | /* |
466 | * Make sure all peer records have been discarded. | |
467 | */ | |
468 | void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet) | |
469 | { | |
470 | struct rxrpc_peer *peer; | |
471 | int i; | |
472 | ||
473 | for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) { | |
474 | if (hlist_empty(&rxnet->peer_hash[i])) | |
475 | continue; | |
476 | ||
477 | hlist_for_each_entry(peer, &rxnet->peer_hash[i], hash_link) { | |
478 | pr_err("Leaked peer %u {%u} %pISp\n", | |
479 | peer->debug_id, | |
480 | atomic_read(&peer->usage), | |
481 | &peer->srx.transport); | |
482 | } | |
483 | } | |
484 | } | |
485 | ||
8324f0bc DH |
486 | /** |
487 | * rxrpc_kernel_get_peer - Get the peer address of a call | |
488 | * @sock: The socket on which the call is in progress. | |
489 | * @call: The call to query | |
490 | * @_srx: Where to place the result | |
491 | * | |
492 | * Get the address of the remote peer in a call. | |
493 | */ | |
494 | void rxrpc_kernel_get_peer(struct socket *sock, struct rxrpc_call *call, | |
495 | struct sockaddr_rxrpc *_srx) | |
496 | { | |
497 | *_srx = call->peer->srx; | |
498 | } | |
499 | EXPORT_SYMBOL(rxrpc_kernel_get_peer); | |
f4d15fb6 DH |
500 | |
501 | /** | |
c410bf01 | 502 | * rxrpc_kernel_get_srtt - Get a call's peer smoothed RTT |
f4d15fb6 DH |
503 | * @sock: The socket on which the call is in progress. |
504 | * @call: The call to query | |
1d4adfaf | 505 | * @_srtt: Where to store the SRTT value. |
f4d15fb6 | 506 | * |
1d4adfaf | 507 | * Get the call's peer smoothed RTT in uS. |
f4d15fb6 | 508 | */ |
1d4adfaf DH |
509 | bool rxrpc_kernel_get_srtt(struct socket *sock, struct rxrpc_call *call, |
510 | u32 *_srtt) | |
f4d15fb6 | 511 | { |
1d4adfaf DH |
512 | struct rxrpc_peer *peer = call->peer; |
513 | ||
514 | if (peer->rtt_count == 0) { | |
515 | *_srtt = 1000000; /* 1S */ | |
516 | return false; | |
517 | } | |
518 | ||
519 | *_srtt = call->peer->srtt_us >> 3; | |
520 | return true; | |
f4d15fb6 | 521 | } |
c410bf01 | 522 | EXPORT_SYMBOL(rxrpc_kernel_get_srtt); |